At the end of the G7 summit in Cornwall, the PM said countries were rejecting "nationalistic approaches".
He said vaccinating the world would show the benefits of the G7's democratic values.
There was also a pledge to wipe out their contribution to climate change.
After the first meeting of world leaders in two years, Mr Johnson said "the world was looking to us to reject some of the selfish, nationalistic approaches that marred the initial global response to the pandemic and to channel all our diplomatic, economic and scientific might to defeating Covid for good".